In auctions with externalities, it is well-known that the core can be empty, which is undesirable both in terms of … stability and fairness. Nevertheless, some auction outcome must be chosen. We separate deviations into two types: deviations by …

taxation, commodity taxation, tax expenditures, externalities, public goods, capital income and wealth taxation, social …

I study auctions in which firms bid for licenses that reduce their marginal costs in a post-auction downstream market …. When there are three or more firms, I show that the Vickrey--Clarke--Groves (VCG) auction maximizes consumer surplus in … surplus is ambiguous. When the VCG auction does not maximize consumer surplus, I show that consumer surplus can be maximized …